It's a huge honour for the Brumbies leader, who has earned the opportunity to lead his country less than three months after debuting against The British & Irish Lions in June and in just his seventh Test for the Wallabies.

Mowen's ascendency comes earlier than expected for the talented backrower, with James Horwill currently sidelined through injury and Brumbies team-mate Nic White winning his first run-on Test cap at scrum-half in place of veteran playmaker Will Genia.

White has played all three of his Tests from the bench since debuting against New Zealand in Sydney last month and has now earned the right to wear the Wallabies number nine jersey for the first time.

His selection in the starting XV caps off a stellar year for the 23- year-old, who also played an influential role in the Brumbies' Super Rugby finals campaign and also in their historic victory over The British & Irish Lions.

The change at scrum-half is one of four made to Wallabies coach Ewen McKenzie's side, with Ben Alexander also re-gaining his place at tight-head prop. Powerful 125kg New South Wales Waratahs lock Sitaleki Timani will bring size and starch in his return to the Australia fold and has been included on a bench which also includes Brumbies outside back Tevita Kuridrani.

McKenzie said it was tough to bench Genia but also believed White had earned an opportunity to start against Argentina.

"The fact that Will has captained his country shows what high regard we hold him in and while he is naturally disappointed, I also know how competitive he is and I've got no doubts he will train himself to a standstill to bounce back as a better player," McKenzie said. "We've spoken about what areas we believe he can continue to improve and evolve his game and he was receptive to going back and addressing those things. In the end, it wasn't an easy decision because he is undoubtedly a world-class player.

"However, we also feel Nic has earned an opportunity to start and will add his own uniqueness and point of difference to how we want to play this game. Nic has had a great season with the Brumbies and has brought his own brand of energy and hard work to the Wallabies group. We've all been impressed by the contributions he has made to the team and in training and we now look forward to seeing him bring his skills to the fore of the pressure cooker on Saturday night."

The Wallabies are spending the week in Perth, where they will be aiming to capture their first victory of the 2013 Rugby Championship against a vastly-improved Argentinean side. McKenzie said he was disappointed by the performances of the Wallabies to this point but was confident they could turn it around by adjusting some elements of their gameplan.

"We made it clear before our first game against New Zealand that this group had very strong ideas around how they wanted to approach and play each game," he said. "Australian rugby is renowned for smart, attractive and running rugby and there is a continued determination from the coaching staff and players to play with ambition and flair.

"We aren't moving away from this philosophy. Within this framework, though, we've worked hard during the week to provide the team with further clarity on certain areas to ensure we are making smarter decisions in different parts of the field. By doing this we will endeavour to remove some of the pressure we are applying on ourselves and shift that pressure to the opposing team. Rugby is a game of chess and we will look forward to the challenge of getting the right balance and our first Rugby Championship win."

Last year's back-to-back victories by the Qantas Wallabies in EDGE Rugby Championship set a new record for the most wins in succession by Australia over Argentina, extending the current winning streak from 2000-2012 to six.